From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D4EEC55179 for ; Wed, 28 Oct 2020 21:42:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D561246AB for ; Wed, 28 Oct 2020 21:42:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603921378; bh=+Cj4JDv/9Kdz/kOl1C3lm3VVi/UOikFi55ZuJNA/YoI=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:List-ID: From; b=ydiehO+satAXdbrA8aOvkSASq7IJIKwh3YoFtbsL6rtne2tqv1bua43lRVUiv5O4/ i/B4q9+wM5ZbiY96/Bw5SB1L/zl9rb7uGBjZi1VB14B8wYNfm94y704fLAwrzsheTO hkUas1N2aBTotueSC05hx3BZhl5EhvurkFBI1a2g= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726174AbgJ1VmZ (ORCPT ); Wed, 28 Oct 2020 17:42:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:38142 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725849AbgJ1VmY (ORCPT ); Wed, 28 Oct 2020 17:42:24 -0400 Received: from paulmck-ThinkPad-P72.home (50-39-104-11.bvtn.or.frontiernet.net [50.39.104.11]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 19729246CD; Wed, 28 Oct 2020 21:02:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603918949; bh=+Cj4JDv/9Kdz/kOl1C3lm3VVi/UOikFi55ZuJNA/YoI=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=us4bztrI2KapLmU1CUulDdhGbWUnIfT0eq/O/r7fhD/uj1XbHv/m0fp59fI6Q6/ru b9toWkeNm6ZmXCQHNgJQkal5IBZV89lV/0ZK5Xdn6K8bdbVp8uLd5lEhjPX7erC+Ub AZ3EziopAvHlTGvy2wkA7iesN2CZyU4nwB2Kke6Q= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id B408435229CE; Wed, 28 Oct 2020 14:02:28 -0700 (PDT) Date: Wed, 28 Oct 2020 14:02:28 -0700 From: "Paul E. McKenney" To: Qian Cai Cc: Boqun Feng , "Peter Zijlstra (Intel)" , Steven Rostedt , Ingo Molnar , x86 , linux-kernel@vger.kernel.org, linux-tip-commits@vger.kernel.org, Linux Next Mailing List , Stephen Rothwell Subject: Re: [tip: locking/core] lockdep: Fix lockdep recursion Message-ID: <20201028210228.GI3249@paulmck-ThinkPad-P72> Reply-To: paulmck@kernel.org References: <160223032121.7002.1269740091547117869.tip-bot2@tip-bot2> <20201012031110.GA39540@debian-boqun.qqnc3lrjykvubdpftowmye0fmh.lx.internal.cloudapp.net> <1db80eb9676124836809421e85e1aa782c269a80.camel@redhat.com> <20201028030130.GB3249@paulmck-ThinkPad-P72> <8194dca3b2e871f04c7f6e49672837f8df22546f.camel@redhat.com> <20201028155328.GC3249@paulmck-ThinkPad-P72> <7cd579ccdacb4f672cf2dc3a0d4553d1845e7ebf.camel@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7cd579ccdacb4f672cf2dc3a0d4553d1845e7ebf.camel@redhat.com> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Wed, Oct 28, 2020 at 04:08:59PM -0400, Qian Cai wrote: > On Wed, 2020-10-28 at 08:53 -0700, Paul E. McKenney wrote: > > On Wed, Oct 28, 2020 at 10:39:47AM -0400, Qian Cai wrote: > > > On Tue, 2020-10-27 at 20:01 -0700, Paul E. McKenney wrote: > > > > If I have the right email thread associated with the right fixes, these > > > > commits in -rcu should be what you are looking for: > > > > > > > > 73b658b6b7d5 ("rcu: Prevent lockdep-RCU splats on lock > > > > acquisition/release") > > > > 626b79aa935a ("x86/smpboot: Move rcu_cpu_starting() earlier") > > > > > > > > And maybe this one as well: > > > > > > > > 3a6f638cb95b ("rcu,ftrace: Fix ftrace recursion") > > > > > > > > Please let me know if these commits do not fix things. > > > While those patches silence the warnings for x86. Other arches are still > > > suffering. It is only after applying the patch from Boqun below fixed > > > everything. > > > > Fair point! > > > > > Is it a good idea for Boqun to write a formal patch or we should fix all > > > arches > > > individually like "x86/smpboot: Move rcu_cpu_starting() earlier"? > > > > By Boqun's patch, you mean the change to debug_lockdep_rcu_enabled() > > shown below? Peter Zijlstra showed that real failures can happen, so we > > Yes. > > > do not want to cover them up. So we are firmly in "fix all architectures" > > space here, sorry! > > > > I am happy to accumulate those patches, but cannot commit to creating > > or testing them. > > Okay, I posted 3 patches for each arch and CC'ed you. Very good! I have acked them. > BTW, it looks like > something is wrong on @vger.kernel.org today where I received many of those, > > 4.7.1 Hello [216.205.24.124], for recipient address the policy analysis reported: zpostgrey: connect: Connection refused > > and I can see your previous mails did not even reach there either. > > https://lore.kernel.org/lkml/ It does seem to be having some difficulty, and some people are looking into it. Hopefully soon someone who can actually make the needed changes. ;-) Thanx, Paul